US707372A - Electrochemical generator. - Google Patents

Description

No. 707,372. Patented Aug. I9, |902. H. S. AMWAKE. ELECTBOCHEMICAL GENERATOR.

'Application filed June 13, 1902.)

(No Model.)

lllflulllllvnalurnnnunnnl/ UNTTEE STATES PATENT OFFICE.

HARRY S. AMWAKE, OF CAMDEN, NEW JERSEY, ASSIGNOR TO CHARLES H. GRAHAM AND GEORGE D. BOUTON, OF PHILADELPHIA, PENNSYLVANIA.

'E EECTRQCHEMICAL GENERATOR.

Y SPECIFICATION forming part of Letters .Patent No. 707,372, dated August 19, 1902.

l i Application-filed June 13, 19072. Serial No. 111,556. (No model.) l

To LZZ whom, it may concern-.-

Be it knownthat I, HARRY S. AMWAKE, a citizen of the United States, residing'in the city and county of Oamden,'State of New Jer-- described in'my Patent No. 702,760, dated June 17, 1902.V In accordance with the invention of said application I surround the positive or negative electrode of a single-Huid electrochemical generator by a current-conducting baftle of such nature as will retard ducting substance or compound, and it may.

be either porous or dense in structure. One object of this baffle is to prevent the circulation of the electrolyte or the motion of the free electrolytic ions from one electrode di,- rectly to the other and to do away with the harmful results brought about by such direct circulation or movement in ordinary singlefluid batteries. Another object of the baffle is to give to the electrolytic circulationl more or less dened paths, determined by the location of the baffles with reference to the electrode, whereby a ow of the electrolyte shall be produced which shall not be local and confined to small portions of the area of the electrode, but which shall take in large surfaces of the entire electrode and which shall-reach and be refreshed by the main body of theelectrolyteof the electrochemical generator. Still a third object of `this baffle is to reduce the thickness of the electrolyte between the two electrodes to a greater extent than hashighly resisting electrolyte. This baille therefore enables me to place the electrodes at a sufficient distance apart so that their undue proximityshall not produce harmful results, and yet not to introduce as much Vresistance between the electrodes as it is .necessary to introduce in ordinary batteries not supplied with the baffles when the velectrodes of such batteries are placed at their minimum distance apart. In fact, in the practical application of my invention I am enabled to use a baille insuch relation to the electrodes that the electrolyte between the baiile and the electrodes shall, in effect, amount to no more than a mere film, which means that my battery has, other things being equahasmall internal resistance and consequent high efficiency. l

Independent of any considerations of the-` ory involved in the operation of my baffle,

` some of which have .been outlined above, I

may say, speaking from a practical standpoint, that the use of my baffle enables me to `operate electrochemical generators so that the energy which is represented by the'chemical action does not much exceed the energy represented by the current which is givenv ,electrode or electrodes. l

In this connection attention is called to the tive electrode in charging becomes the negative electrode in discharginga corresponding remark applying to the other electrode. With the construction shown in my former application, in which the baffle surrounds the positive or negative electrode only, it would be necessary in ordinary constructions of accumulatore to do without the full advantage of the baille either in charging or dischargfact that in electrical accumulators the posi- IOO ing. In the present invention the same generator and bafes without change will act with high efliciency both in charging and discharging.

In the drawings, Figure l is a plan of my electrochemical generator. Fig. 2 is a vertical cross-section on the line 2 2. Fig. 3 is a vertical cross-section on the line 3 3, and Fig. t is a detail.

The generator consists of the usual cell or case I), containing the electrolyte, and the usual positive and negative electrodes A and A, respectively. These electrodes may be held in position by being inserted in slots in an insulating bridge-piece F, as shown.

Surrounding the electrodes A and A are the baffles B and B', respectively. These baffles may also be fastened in position by being insertedin slots or grooves in the bridge-piece F, although it is to be understood that this bridge-piece is merely one of a number of supporting and retaining devices which may be employed. The baffles B B', as seen, completely surround the electrodes; but they do not inclose them, for these baffles are open at their lower ends. This prevents a circulation of the electrolyte from one electrode directly across to the other electrode. Such circulation must naturally take a somewhat circuitous path down through the bottom of the baffle. Itseems that the free electrolytic ions must take the same path. The baffles are normally insulated from the electrodes. Disregarding the electrolyte,they may or may not be insulated from each other. In fact it is sometimes of advantage to mechanically connect them, in which case they would usually, though not necessarily, be electrically connected. One of a number of such constructions I have shown in Fig. 4, in which the baffles B and B are built of a sheet of lead bent into H form, the two thicknesses of the metal forming the cross-piece of the H being pressed closely together, so as to leave nospace therebetween for the passage of the electrolyte. The electrodes A A are placed within spaces represented by each vertical leg of the H structure and may bein the form of very thin films. As explainedin my aforesaid patent, the heat generated by the electrolytic action will be greater near the vertical central portion of the electrodes than at the two vertical edges of the electrodes. This will cause a convection-current upward along the center of the electrodes and downward at the edges of the electrodes,which is far more beneficial in action than the multiplicity of ill-defined and purely local convection-currents set up in ordinary batteries. Furthermore, it will be noticed that when the convection-currents set up within my baille reach the bottom of the baille they will naturally draw in fresh electrolyte from the body of the electrolyte found in the cell. In this manner fresh electrolyte at a uniform strength is kept in constant renewed contact with the entire surface of the electrode, which results in the case of primary batteries, as I have particularly demonstrated, in a more thorough chemical action and in causing the electrode to wear away uniformly over its entire surface. I may add that I am enabled to use an electrolyte of a more than usually high specific gravity, which also adds to the battery eliiciency. The baffle, as I have before said, must be a conductor, although it need not be necessarilya good conductor,aud I may make it of carbon, which is a material well adapted for the purpose, or of lead or iron or of many other suitable materials.

Where demands for an extraordinary charge of current occur for short periods of time, the baflle B may be placed in parallel circuit with the electrode A by means of the current-leads a b. At the same time the baffle B may be placed in parallel circuit with the electrode A by means of the current-leads a b. The material of the baffle in this case may be the same as that of the electrodethat is, if I use electrodes of lead I may make my baffles of lead. At the same time I may make my baffles of a different material, such as carbon, even though my electrodes are made of lead.

What I claim lsl. An electrochemical generator consisting of a single-Huid cell, provided with a positive electrode, a negative electrode, an electrolyte and current-conducting baffles in said electrolyte respectively surrounding each of said electrodes and normally insulated therefrom, substantially as described.

2. An electrochemical generator consisting of a single-fluid cell, provided with a positive electrode, a negative electrode, and an electrolyte, current-conducting baffles in said electrolyte respectively surrounding each of said electrodes and normally insulated therefrom, and means for placing in parallel circuit each electrode and its surrounding baiile.

3. An electrochemical generatorconsisting of a single-fluid cell provided with a positive electrode, a negative electrode, an electrolyte and mechanicallyconnected current -conducting bai'iies in said electrolyte respectively surronnding each of said electrodes and normally insulated therefrom, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

HARRY S. AMWAKE.

lVitnesses:

WATSON B. RULoN, Jol-IN A. WIEDERSHEIM.

ICD

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